Update freeamp 2.1.1 to zinf 2.2.0.
Add zlib patches for working around zlib 1.1.4 problems (obtained from
src/lib/zlibz in current) + a file that was forgotten in the zlib 1.1.3 to
1.1.4 upgrade between freeamp 2.1.1 and zinf 2.2.0.